Device-to-device (D2D) communication is a new technology that allows direct communication between devices. The D2D communication can improve spectral efficiency of a cellular communications system, reduce transmit power of a device, and implement short-range communication between devices.
In a whole D2D communication process, device discovery is a start and a prerequisite for performing the D2D communication. In the prior art, a communication device listens on a D2D discovery resource, to receive and process D2D discovery information sent by another D2D communication device. The discovery information includes a pilot signal and device information. When a first communication device receives D2D discovery information sent by a second communication device, time-domain correlation is performed on a pilot signal and a local pilot sequence, so as to obtain time when a discovery signal of the second communication device arrives at the first communication device, and parse the discovery information to obtain device information of the second communication device, so that the first communication device can discover the second communication device.
However, a device that performs D2D communication consumes much power in the prior art.